# -*- coding: utf-8 -*-
# @Time : 2024/2/1 16:37
# @Author : ZH
# @File : 25.py
# @Software: PyCharm

class ListNode(object):
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next


class Solution(object):

    def reversal(self, l, r):
        end = r.next
        start = l


    def reverseKGroup(self, head, k):
        """
        :type head: ListNode
        :type k: int
        :rtype: ListNode
        """
        if k <= 1: return head
